Feature Request: Set shell in ShellCommand

For example, On windows, you could use git bash to execute shell scripts, using same paths/args etc as *nix build steps

WSL is another option for windows 10

Start by locating the ShellCommand entry point and reviewing how shell scripts are executed for Windows and Unix-like build steps. Determine how a configurable shell should support Git Bash or WSL while preserving paths and arguments, then add coverage for the selected behavior.

Written by the indexing model from the issue text.